Dextranases are .alpha.-1,6-glucanases (E.C. 3.2.1.11), also known as 1,6-.alpha.-D-glucan 6-glucanohydrolases, which degrade the .alpha.-1,6-glycosidic linkages in dextran.
Dextranases are known to be useful for a number of applications including the use as ingredient in dentifrice for prevent dental caries, plaque and/or tartar and for hydrolysis of raw sugar juice or syrup of sugar canes and sugar beets.
Several micro-organisms are known to be capable of producing dextranases, among them fungi of the genera Penicillium, Paecilomyces, Aspergillus, Fusarium, Spicaria, Verticillium, Helminthosporium and Chaetomium; bacteria of the genera Lactobacillus, Streptococcus, Cellvibrio, Cytophaga, Brevibacterium, Pseudomonas, Corynebacterium, Arthrobacter and Flavobacterium, and yeasts such as Lipomyces starkeyi.
A commercially available dextranase, sold as an industrial enzyme for breaking down raw sugar juice, is Dextranase 50L from Novo Nordisk produced by fermentation of a strain of Paecilomyces sp.
Below are summarised prior art documents concerning dextranase and applications thereof.
Prior Art Documents
EP 663 443 (Centro de Ingenieria Genetica y Biotechnologia) describes a dextranase derived from Penicillium minioluteum. The dextranase can be expressed heterologously in the yeast Pichia pastoris. Said recombinant enzyme has an optimum temperature in the range from 55.degree. C. to 60.degree. C., a N-glycosylation percentage between 13 and 15% and a half-life time of about 7.6 hours at 50.degree. C.